  {/* console.log('开始canvas绘制之旅'); */}
  const canvas = document.getElementById('canvas')
  // 这个设置的是元素的大小
  canvas.style.width = '400px';
  canvas.style.height = '200px';
  
  // 直接设置属性，不用加单位，这个是绘制区域的宽高
  canvas.width = 400
  canvas.height = 200
  
  // 绘制上下文
  const context = canvas.getContext('2d');
  
  context.fillStyle = 'red'
  context.strokeStyle = 'yellow'
  context.lineWidth = 10
  context.strokeRect(0, 0, 100, 100)  // 绘制边框
  context.fillRect(5, 5, 95, 95)
  
  context.fillStyle = 'black'
  context.font = "25px PingFangSC-Regular, sans-serif"
  context.fillText("hello world", 150, 100)
  